The present invention pertains to heat shields for gas turbine engines and, more particularly, to a method and apparatus for inhibiting air leakage between adjacent flow path liners, such as vane liners, at the radially outer ends of stationary compressor vanes.
In prior art gas turbine engines, flow path liners, such as the vane liners in the compressor stage of the engine, are typically secured to the outer casing by hooks which are slidably connected to the casing wall. Such a connection results in a leak path which allows hot gases to flow between the casing and vane liner. The smooth sides of the vane liner and casing provide an unimpeded flow path in which the velocity of hot gases is undiminished with resulting convection heat transfer to the casing and vane liner. Those skilled in the art realize that heat can be transferred by convection and conduction with a particular convective heat transfer coefficient being determined by the hot gases and the medium over which the hot gases flow. The greater the velocity of the gases over the medium, the greater the heat transfer. Such undesired heat transfer can cause thermal damage and distortion to the casing and reduce performance.
Thus, a need exists for a mechanism for impeding the velocity of gases which flow in the leakage paths provided by the gaps formed between the casing and sides of a vane liner.